Picture courtesy of Wikipedia; click for full size
The rollout for what would eventually become the most popular GUI OS of all time was relatively inauspicious. Microsoft announced demoed its Windows project in late 1983, but wasn't able to actually be brought to market in 1985, and, to prevent legal trouble from Apple, had certain features (like the ability for Windows to overlap) disabled. Essentially just a front-end to DOS and with no Windows-only killer apps, Windows would languish until the release of version 3.1 in the early '90s.
This video shows Windows 1 in action: